Reliable psychiatric assessment procedures for use with young children are needed in clinical practice and in research. Procedures for children of these ages have been developed as part of a study of normal and depressed mothers and their offspring. Two kinds of instruments have been developed. The first relies on the child-clinician dyad in a semi-structured play interview. Assessment is in terms of areas of concern (following a standardized set of categories) and of DSM III diagnoses. A second instrument brings together the strengths of clinical psychiatry and child development. Mother and child are observed together in standard situations that involve conditions and requirements that are natural parts of the child's life (stress, closeness, pleasure, mother-unavailability, frustration, etc.). The situations are sequenced to comprise a reasonable script of events. Behaviors are coded by the clinician; the analysis combines a prescribed set of coding judgments, and clinical assessments. The sample consists of 102 children, 1 1/2 to 5 years. The assessments from the two procedures are being compared and evaluated against a number of criteria within the larger study of child development in families with and without psychopathology.